This ranks among the more dismaying moments in a decade-long war. Americans have worked for years to position themselves as protectors of Afghans against murderous insurgents, and then yesterday a U.S. Army sergeant surrendered after a shooting rampage that left well over a dozen people dead. The list of those killed includes women and children, and the motive for the suspect remains unclear.

NPR's Quil Lawrence is following this story and its aftermath from Kabul. And Quil, how certain are authorities about what happened here?

QUIL LAWRENCE, BYLINE: We're still getting some details. The original reports from the U.S. military that there was one soldier who'd walked off a base in the middle of the night, carried out these killings, and then returned and surrendered himself - that's essentially still the line we're getting from U.S. officials.

But village elders in the district of Panjwai we spoke with this morning said that these attacks took place in two different hamlets. One was a quarter mile outside the American base and the other hamlet about a mile away. In the first village, 11 people died in one family, most of them young children in one house. Their bodies were apparently gathered up under some blankets, which were then set alight, which explains some of the burn marks that are visible in photographs we've seen of the bodies.

Elders said that the locals believed there were many Americans involved, not just one. U.S. officials say that they have one man in custody but they have admitted it's still an open question whether other soldiers might have been involved.

INSKEEP: And if you imagine one man, you can imagine, I suppose, someone who might have snapped, who might be deeply troubled, but if it's more than one person it's a completely different situation.

LAWRENCE: Yes. We do have a precedent. From the same region of the country last year the news broke that there had been something that is now called the Kill Team, a group of American soldiers who had been shooting Afghans for sport. And one of them has been sentenced to several life sentences for murder in the United States. But we just don't know now whether their might have been other people involved.

We have heard from the U.S. military that there was no official operation going on in the area at the time.

INSKEEP: How have Afghans been reacting to this, Quil?

LAWRENCE: Well, civilian casualties have been the incendiary issue here for years and years, and that's just when they're pretty clearly accidental - bombs that went astray or fog of war or stray bullets, this kind of thing. This massacre, I think, is unprecedented. At this hour there haven't been major protests. There have been fiery denunciations in the press. They do seem to breaking down somewhat along ethnic lines, which maybe shows some fear that the incident might hasten an American withdrawal from Afghanistan.

One relative of the murdered civilians told President Karzai, despite your repeated calls for preventing the killing of civilians, American forces have again killed innocent people and are oppressing us.

Commentators from the north of the country - non-Pashtuns - have been more often calling for calm, and even directly saying that they are afraid that if Americans leave too soon there will be some sort of a North/South civil war in Afghanistan with the non-Pashtuns in the North uniting against the South and the Taliban.

INSKEEP: So we have some ethnic groups that see themselves as being protected by the Americans more so than others. What about the government at the center, President Hamid Karzai?

LAWRENCE: Well, he had just finished making a very conciliatory speech yesterday when the news of this massacre broke. And he spoke again condemning what he called premeditated murders. He's in a very tough spot. Observers say he really needs a strategic partnership deal with the U.S. to keep his government going forward to the future with some stability. But just as he started coming out in favor of this and trying to persuade the public again that there needs to be a U.S. presence here long-term, this news broke. And Karzai's from the same area where the killings took place. He really needs to show people that he's angry.

INSKEEP: Does this put U.S./Afghan relations back to zero?

LAWRENCE: It's possible. They had just started to recover from all of the riots and the violence after the Quran burning incidents last month. The U.S. mission here, diplomats as well, were just starting to get off this complete lockdown. And this is a time when the mission in Afghanistan is supposed to be transitioning to one where Americans will be in smaller numbers and be training Afghans, something that pivots on trust, and that trust is severely strained right now.

INSKEEP: NPR's Quil Lawrence is in Kabul, Afghanistan.

Quil, thanks very much.

LAWRENCE: Thank you, Steve.

INSKEEP: So that's the situation in Afghanistan. We'll keep you up to date as that story develops. Transcript provided by NPR, Copyright NPR.